What To Do When Your Bee Blocks Fill Up (And How to Make a Simple Release Box)

By Dr. Jessica Forrest and Ryan Brideau

After your bee home has been up for a few weeks, you might have noticed that some blocks have been sealed up at the front. This can take many forms, from a simple mud cap common among some mason bees and solitary wasps, to a greenish plug made from bits of leaf and other material from a leafcutter even some other mason bee species, to the clear, glass-like cap of a yellow-face bee, among countless other variations.

So, what now? Well, that's up to you! Let's talk about a couple of options.

The Easy Way

Do nothing! You're welcome. Have a nice day.

But seriously, you can just leave them there year-round without any concern. While you may come across some articles that say you need to clean the blocks and refresh the nesting material each year or else you risk creating a health issue for your bees, that's really only the case when you are trying to raise many bees in a high concentration, or you use nesting materials that are prone to rot and mould.

If instead you're using one of our bee homes, you have little to worry about. The density is low, so there's little risk of having a negative impact on the population of bees in your area, and our blocks are made of a hardwood that lasts a very long time outdoors and can be reused year after year. This design has been used for over half a century by scientists studying wild bees without issue, so you can sleep soundly and let nature run its course.

However, if you are worried about predators like birds making a snack out of your bee home, or you want to provide empty nesting sites for bees that are coming out later in the season, read on!

The Fun Way

If you want to "tend" to your bees, now would be a good time to check up on your blocks. With our bee viewing blocks, you can open each one and see if anyone is living inside. If you notice any spiders, earwigs or other creatures you don't want living there, you can evict them by pulling off the acrylic window and giving them a poke with a stick. (Also, if you are having a problem with any crawling insects, stay tuned - we'll be releasing our crawling insect barriers soon.)

If you have our regular bee blocks, peek in the front with a flashlight to see if you can see any finished nests. Sometimes the end of a nest will be set back an inch or so from the front, and you'll only be able to see it if you look carefully with a light. This can be because the mother bee chose to finish her nest there, or because she abandoned it before putting the final plug in, as shown with the leafcutter nest below.

When you find a finished nest, remove the block from the bee home and tuck it away somewhere safe from predators that still gets the full range of temperature changes through the year. Examples would be on a covered patio, in an unheated garage or in a release box (which we'll talk about below). You can now replace the block that you removed with a fresh block (and if you need some more, you can purchase them from us here: Bee Blocks and Stands).

Making A Release Box

A release box is a simple idea: it's a box that you place your bee blocks in to keep them safe, which allows them to leave when they emerge from the nest, but doesn't allow them to come back. (In practice, things don't always go that smoothly: in the field we've found that some bees and wasps will return to the block even if it is inside a release box, but it at least lowers the odds of that happening.)

The main reason you'd want something like this is to reduce how long the nests are exposed to predators like birds, while allowing you to clean the blocks out once the young have left (and before anyone else has moved in), if you feel so inclined.

While you can build a very nice release box that makes it easy to view the progress of your bees (hint: we may be working on one), here we'll cover the simplest possible design: one made from the very cardboard box that we ship our bee homes in. All you need to do is puncture a hole in a side big enough to let the largest bees out - about the size of a dime is more than enough:

Place your completed blocks inside:

Close it up, and put it somewhere where it won't get rained on, and that bees can escape if they emerge:

That's it! The main thing to avoid here is putting too many blocks in one location, as high densities of nests bring problems like becoming a buffet for parasitic wasps, and nobody wants that.

As always, if you have any questions at all, feel free to reach out to us by email or chat here - we're happy to answer any questions you have.